Method of producing alloy printing cylinders



p 1954 E. H. JOHNSON 3,150,014

METHOD OF PRODUCING ALLOY PRINTING CYLINDERS Filed Oct. 18, 1962 99+Z Zn, BALANCE FIG.3

TREAT AT 525 F.550 F. FOR lzHR. AND EXTRUDE L! J TO FIG.4 DIMENSIONS FIG.5

INVENTOR. EDWIN H. JOHNSON, DECEASED BY HARRIET B. JOHNSON, BY: EXECUTRIX ATTORNEYS United States Patent 3,150,014 METHOD 0F PRODUCING ALLOY PRINTING CYLINDERS Edwin H. Johnson, deceased, late of Pompano Beach, Fla,

by Harriet B. Johnson, exeeutrix, 948 Irving Ave., Dayton, Ohio Filed Oct. 18, 1962, Ser. No. 231,601 3 Claims. (Cl. 148-2) This invention relates to the production of essentially zinc cylinders that can be engraved to afford a printing cylinder.

It is common practice in the graphic arts accurately to print form sheets such as tabulating cards, invoice sheets and the like, with an expensive engraved copper cylinder. It would be highly advantageous to be able to accomplish this with an engraved zinc cylinder. However, it has heretofore not been possible to achieve satisfactory production of sound cylinders of zinc that can be engraved to afford a printing cylinder of the aforesaid kind, and the primary object of the present invention is to accomplish this by subjecting a particular zinc alloy to a particular sequence of steps resulting in an accurately sized and metallurgically sound zinc cylinder which can be engraved resulting in a zinc printing cylinder capable of printing numerous copies.

Specifically, it is an object of the present invention to achieve production of zinc cylinders of the aforesaid kind by first casting a sleeve of an alloy which is approximately 99+% zinc, balance addition elements consisting of aluminum and magnesium. Specifically, the aluminum content is about 0.30.6% and the magnesium content about 0.025%. The cast body, removed from the mold, is transferred immediately to a heat treating furnace or oven where it is held for about one-half hour at about 525-550 F.

The zinc sleeve thus soaked at temperature is transferred immediately to an extruding die where the sleeve is extruded approximately to the finished dimensions. The final step is to machine the extruded sleeve to the finished dimensions. It is found that the foregoing steps performed on the designated alloy result in a sound, strong, essentially zinc cylinder capable of being acurately engraved to afford a durable printing cylinder capable of long printing runs.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawing which, by way of illustration, shows a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is an elevational view of a cylinder suitable for engraving produced under the present invention;

FIG. 2 is an elevational view of a primitive form of the cylinder as initially cast;

FIG. 3 is a schematic view of the casting operation;

FIG. 4 is an elevational view of the casting after extrusion; and

FIG. 5 is a view of the extruded cylinder in a semifinished state.

The cylinder illustrated in FIG. 1 in the drawing represents the engravable zinc cylinder ultimately to be obtained under and in accordance with the present invention. The manner in which the various dimensions of the cylinder are obtained play an important role in the present invention, and consequently the finished dimensions indicated by alphabet characters in FIG. 1 have the following values for the finished cylinder 10:

a=2.345" b=3.750" c=2.093" 11:1.937"

Thus, it will be noted that the cylinder 10 includes a uniform outside diameter, but the internal diameter thereof tapers from the larger value c to the smaller value a. This is in compliance with the character of the so-called Carroll printing press in which the engraved cylinder 10 is employed.

In achieving the cylinder 10, capable of being engraved, a primitive shape in the form of a rough sleeve-like slug 11, FIG. 2, is first cast. The slug 11 has a shorter length than the finished part 10, but the outside diameter thereof is substantially larger than the part 10. Specifically, the dimensions for the casting 11 are as follows:

The casting 11 is cast of an alloy of the Vitaplate type furnished by Imperial Type Metal Co., reported to analyze about 0.30.6% aluminum, about 0.025% magnesium, balance zinc.

The aforesaid alloy in ingot form is melted in a crucible or the like and poured into the mold 13, FIG. 3, at 1025l050 F. It should be noted that the temperature of the molten metal in the melting pot is maintained for 30-40 minutes before pouring.

The casting in the mold 13, FIG. 3, is allowed to stand for 30-40 seconds, and thereafter the cast part 11, having the dimensions noted above, is stripped from the mold, and the sprue and gate (not shown) are removed from the cast part 11.

The crude, cast slug 11 is transferred to a heat treating furnace or oven and there held at 525550 F. for about one-half hour. The part thus soaked at temperature, when the foregoing condition has been achieved, is then transferred immediately to an extruding die where the crude casting 11 is extruded immediately to produce a machinable part 12, FIG. 4, having the following dimensions:

The part 12, it will be noted, has a dimension b just slightly larger 04;") than the dimension b of the finished cylinder, and the outside diarneter thereof is larger than the dimension a of the finished part. Consequently, the extruded part is lathe-turned to an outside diameter of 2.380", and the two ends thereof are faced to the finished dimension of 3.750", producing the semi-finished cylinder 13, FIG. 5.

It is found that the extruding operation distorts the internal taper bore of the cylinder, whereby the bore is slightly curved rather than straight. Therefore, following the facing operations, performed at both ends of the extrusion 12, the interior of the semi-finished cylinder 13 is bored or reamed accurately to the diameters c and d, FIG. 5 (taper =0.500 per foot). Finally, the part 13 is transferred to a taper fixture where the outside diameter is turned to the finished dimension of 2.345", resulting in the part illustrated at 10 in FlG. 1 ready to be photoengraved.

It will be seen from the foregoing that it is possible under the present invention to produce a cylinder, essenforeshortened and thickened cylinder is then heat-treated under specified conditions and immediately lengthened and reduced in diameter by extrusion techniques approximately to the finished dimensions. The final dimensions, including the accurately tapered bore, are attained by machining operations.

What is claimed is:

1. In a method of producing engraved printing cylinders of predetermined length and outside diameter, and a bore of predetermined inside diameter, from an engrav able zinc alloy, which is about 99% zinc, balance consisting of about 0.30.6% aluminum and about 0.025% magnesium, comprising: casting a sleeve-type slug of said alloy foreshortened in length but having a thickness dimension greater than the finished cylinder; heat treating the casting for about one-half hour at about 525550 F. and immediately extruding the heat treated casting to produce an elongated sleeve-type extrusion having a greater length but a lesser thickness dimension than that of the casting; and machining the ends, the outside diameter and the inside diameter of the extrusion to the ing of addition elements consisting of less than 1% each of aluminum and magnesium, comprising: casting a sleevetype slug of said alloy foreshortened in length but of greater thickness than the finished cylinder; heat treating the casting at 525-550" F. and immediately extruding the heat treated casting to produce an elongated sleeve approximately of the dimensions of the finished cylinder; and machining the extrusion to the finished dimensions.

3. In a method of producing engraveable printing cylinders from an engraveable zinc alloy which is about 99% zinc, balance addition elements consisting essentially of less than 1% each of aluminum and magnesium, the steps comprising: casting a body of said alloy having dimensions substantially different from the finished cylinder, extruding the cast body substantially to the dimensions of the finished cylinder, and machining the extruded part to the finished dimensions of the printing cylinder.

- References Cited in the file of this patent UNITED STATES PATENTS 2,011,987 Tainton et a1 Aug. 20, 1935 2,141,813 Finkeldey Dec. 27, 1938 2,365,208 Morris Dec. 19, 1944 OTHER REFERENCES Metals Handbook, 1948 edition, published by the A.S.M., Working of Zinc and Zinc Alloys, by E. H. Kelton, pages 1082-1084 relied on. 

1. IN A METHOD OF PRODUCING ENGRAVED PRINGINT CYLINDERS OF PREDETERMINED LENGTH AND OUTSIDE DIAMEETER, AND A BORE OF PREDETERMINED INSIDE DIAMETER, FROM AN AVERAGEABLE ZINC ALLOY, WHICH IS ABOUT 99% ZINC, BALANCE CONSISTING OF ABOUT 0.3-0.6% ALUMINUM AND ABOUT 0.025% MAGNESIUM, COMPRISING: CASTING A SLEEVE-TYPE SLUG OF SAID ALLOY FORSHORTENED IN LENGTH BUT HAVING A THICKNESS DIMENSION GREATER THAN THE FINISHED CYLINDER; HEAT TREATING THE CASTING FOR ABOUT ONE-HALF AN HOUD 525-550*F. AND IMMEDIATELLY EXTRUDING THE HEAT TREATED CASTING TO PRODUCE AN ALONGATED SLEEVE-TYPE EXTRUSION HAVING A GREATER LENGTH BUT A LESSSER THICKNESS DIMENSION THAN THAT OF THE CASTING; AND MACHINING THE ENDS, THE OUTSIDE DIAMETER AND THE INSIDE DIIAMETER OF THE EXTRUSION OF THE FINISHED DIMENSIONS. 